Frequencies for first 10,000 rows of uop_induc variable in natl2013 dataset :

  Induction |
   of labor |
        U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,667       26.67       26.67
          2 |      7,180       71.80       98.47
          9 |        153        1.53      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015